Vol. 52.] 



A DELIMITATION OF THE CENOMANIAtf. 



121 



base of the Cenomanian at the bed of sandy glauconitic marl, which 

 contains black phosphates (see p. 119), and in this we entirely 

 agree. There is here a well-marked plane of division, for the phos- 

 phate-bed is separated from the marl below by a seam of sand, full of 

 glauconitic grains, a rich brown in the centre, from 2 to 3 inches 

 thick. This brown sand was noticed in all the sections between 

 Cape La Heve and St. Jouin, except at one place, about a mile east 

 of the lighthouses. The soft marl forming the bed itself is full 

 of glauconite, the grains being large as well as abundant ; small 

 quartz-pebbles are not uncommon, and the black phosphatic nodules 

 are not unlike those of the Cambridge Greensand; indeed, an analysis 

 by Berthier quoted by M. Lennier shows that they contain 57 per 

 cent, of phosphate of lime. The following is a list of the fossils 

 collected by one of us from this nodule-bed ; a few marked L are 

 given on the authority of M. Lennier, and we are indebted to 

 Dr. G. J. Hinde, F.G.S., for naming the sponges and polyzoa : — 



PORIFERA. 



Trematocystia siphonioides, Mich. 



d? Orbignyi, Hinde. 



Corynella rugosa, Hinde. 



, sp. 



Elasmostoma consobrinurn, d Orb. 



plicatum, Hinde. 



Jerea, sp. ( = Siphonia). 

 Pachypoterion compactum, Hinde. 

 Stauroncma Carteri, Sollas. 

 Plocoscyphia (?) fragments. 



Hydrozoa. 

 Porosphcsra urceolata, Phil. 



Annelida. 



Ditrupa difformis, Lam. 

 Galeolaria plexus, Sow. 



EcHINODERXIATA. 



Cidaris vesiculosa, Goldf. 



, sp. 



Discoidea svhucula, Klein. 



Goniophorus, sp. 



Salenia, sp. 



Pseudodiadema ornatum, Goldf. 



Benettics, Forbes. 



variolar e, Brongn. 



L Holaster subglobosus, Leske. 



Polyzoa. 



Ceriopora (Ceriocava) mammillaris, 



d'Orb. 

 Diastopora, sp. 



, sp. 



Alecto, sp. 



Melicertes compressa, d'Orb. 

 Sparsicava irregularis, d'Orb. 

 Eadiopora (Domopora) tuberculata, 



d'Orb. 



Polyzoa (continued). 



Eadiopora omata, d'Orb. 

 Micrupora, three species. 



Braciiiopoda. 



Rhynchonella dimidiata, Sow. 



convexa, Sow. 



Grasiana, d'Orb. 



Megerlia lima. Defr. 

 L Terebratula biplicata, Sow. 



Terebrafella pectita, Sow. 

 L Terebrirostra lyra, Sow. 



Lamellibranciiiata. 



Exogyra conica, Sow. 



Rauliniana, d'Orb. 



Ostrea canaliculata, Sow. 



Lesueuri, Sow. 



carinata, Sow. 



Pecten asper, Sow. 



Duiempliana, d'Orb. 



Neithea quadricostata, Sow. 

 Spondylus striatus, Sow. 

 Trigonia spinosa, Ag. (non Park). 

 Cyprina, sp. 



Gasteropoda. 



Avellana cassis (?), d'Orb. 

 Natica (like gaultina). 

 L Pleurotomaria Mailleana, d'Orb. 



perspectiva, Sow. 



Turboidea, sp. 



Cephalopoda. 



Ammonites Mantelli, Sow. 



navicularis, Mont. 



varians, Sow. 



Scaphites esqua/is (a fragment). 

 L Xautilus subradiatus, d'Orb. 

 Turrilites, sp. 



